1. Field of the Inventions
The present inventions relate to a water jet propulsion boat provided with a supercharger for feeding compressed air to an engine.
2. Description of the Related Art
Conventionally, water jet propulsion boats travel on the seawater or the like by driving a jet pump to draw in seawater from the bottom of a hull and eject it from the rear of a stern. Recently, this type of water jet propulsion boat has become available with a supercharger to improve engine output, more particularly, acceleration performance.
For example, Japanese Patent Publication No. JP-A-2003-27952 discloses a water jet propulsion unit having an engine disposed in the longitudinal direction of the hull body so that the supercharger is located rearwardly from a rear side of the engine. The supercharger and a rear end of a main gallery provided parallel to a crankshaft of the engine are connected via an oil feed pipe. This reduces the time period between engine start and oil feeding to the supercharger, which allows the supercharger to quickly and reliably operate.